More bread is being created
Astronomy & Space Exploration
- Thread starter MrMarcello
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In the latest episode of the United Hour Podcast, Nik (@Rood) is joined by CEO Duncan Drasdo and Financial Director Andy Green from the Manchester United Supporters Trust for a special episode on all things behind the scenes at Old Trafford including a brief history of MUST and their aims today, views on INEOS and Sir Jim Ratcliffe so far, and the Old Trafford regeneration.
If that's the case then I don't think that time dilation due to space-time warping or stretching would be relevant in this context. I'm not sure you guys get my point, my fault no doubt.More bread is being created
If a visible event say lasts a day from start to finish and is travelling towards us but the space it travels in stretches, then the light wave will increase in length/red-shift and the event will last longer than a day and will appear to slow down. That's my interpretation of this, I just need to square it with dark energy density etc.
Correct!
As space expands, new space is created. And with it, new dark energy.
The stretching of space due to the expansion of the universe does indeed cause light to be redshifted, which can make events appear to take longer. Time dilation is another phenomenon that can also lead to redshift in certain contexts. And dark energy is a critical component of why the universe's expansion is accelerating, which impacts how much redshift we observe.
Does that answer your question? Kind of?
Yes. That is my understanding as well. And a good clear explanation.
I don't think it specifically answers my quiery although I'm bad for explaining it succinctly. Essentially it's the time dilation with regards to the expansion of the universe? If space-time is stretching then yes time will be slowed down as it does with the space around a massive object, but if more space is being created as the universe expands then theres no warping of space-time and no time dilation.
https://www.forbes.com/sites/starts...universe-expands-does-space-actually-stretch/
This is a great article that seems to say its stretching and building Depending if we're referencing the fabric of space itself or the stuff in it.
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Interesting, although no real proof for it.
"...University of Ottawa adjunct professor Rajendra Gupta has calculated that it is, in fact, 26.7 billion years old – nearly twice as old as the current accepted model...."
https://cosmosmagazine.com/space/as...nct professor,evidence,” says one cosmologist.
"...University of Ottawa adjunct professor Rajendra Gupta has calculated that it is, in fact, 26.7 billion years old – nearly twice as old as the current accepted model...."
https://cosmosmagazine.com/space/as...nct professor,evidence,” says one cosmologist.
I don't think the original research has anything to do with the kind of time dilation you get around extremely heavy objects or with objects going very fast. It's not the "experiencing time differently" kind, but an effect of the extreme redshift of the light coming from the object. Basically we're just observing it in slow motion, but it presumably "happened" at the same speed as most of the Universe.
I think.
It's a different kind of time dilation which isn't a change in relative time to us as you say. But the effect is similar in terms of the stretching/warping of space time that causes red shift/gravitational lensing etc.
I said in post 3602 how it works and should work with space expanding/stretching. The article I posted seems to say that space stretches and new space (dark energy density remains constant) is being created, both are true depending on how we measure the universe. It does help to separate the 2 dilation phenomena though so thank you.
Yeah, there are two types of time dilation: one near massive objects or at high speeds, and another related to the expansion of the universe.
In the universe's expansion, it's not time dilation in the same way. Space between galaxies is growing, rather than stretching like elastic. This gives rise to "cosmological time dilation". As space expands, light from distant objects is stretched. This makes events, like a supernova explosion, appear longer.
As far as I understand dark energy maintains constant density, yet seems to increase as the universe expands.
New space is created?
Where ? In what ?
Not being an asset here just genuinely mind boggled ?
crazy isn't it!When we say "new space is being created," we're referring to the expansion of the universe itself. This doesn't happen in a specific location, like inside galaxies or between stars. It's happening everywhere, all the time. So, new space isn't being created in anything, rather the space between everything is increasing.
The metric expansion of space is one of those things you just have to kinda accept, it's too far outside our normal experience of life otherwise.
My favourite part about it is that as @Shakesy says, it happens everywhere at the same time. Very, very, very, very slowly, but the Universe is so stupidly big that it adds up, and the further apart things are the more space has been created between them. And at some point in the near future, astronomically speaking, our Observable Universe is going to be as big as it's ever going to get, as the distance between us and anything outside of it is increasing by more than the speed of light (technically it is still going to grow for a while even then, but by and large that's true).
Eventually even the things inside of it are going to start fading from view as the light from them redshifts out of our ability to detect them. If we take that far enough, we'll eventually reach a point where anything that isn't our galaxy (at that point a merger of our galactic backyard the Local Group) will have faded from view and be undetectable. Ultimately, any intelligent life that arises in that galaxy will conclude that the Universe is static and eternal, and concepts like the Big Bang and the evolution of the Universe will be unknowable.
Fun times.
My favourite part about it is that as @Shakesy says, it happens everywhere at the same time. Very, very, very, very slowly, but the Universe is so stupidly big that it adds up, and the further apart things are the more space has been created between them. And at some point in the near future, astronomically speaking, our Observable Universe is going to be as big as it's ever going to get, as the distance between us and anything outside of it is increasing by more than the speed of light (technically it is still going to grow for a while even then, but by and large that's true).
Eventually even the things inside of it are going to start fading from view as the light from them redshifts out of our ability to detect them. If we take that far enough, we'll eventually reach a point where anything that isn't our galaxy (at that point a merger of our galactic backyard the Local Group) will have faded from view and be undetectable. Ultimately, any intelligent life that arises in that galaxy will conclude that the Universe is static and eternal, and concepts like the Big Bang and the evolution of the Universe will be unknowable.
Fun times.
I've posted probably that exact thing a few times in this thread, but it just tickles me.
That's even harder to understand!
When we say "new space is being created," we're referring to the expansion of the universe itself. This doesn't happen in a specific location, like inside galaxies or between stars. It's happening everywhere, all the time. So, new space isn't being created in anything, rather the space between everything is increasing.
If new shit is being created between existing shit we must be expanding till allow for new stuff.
New shit is being created, everywhere, but we only notice it on cosmological scale.
The Andromeda Galaxy is 2m ly away and the new shit isn't enough to keep it from falling into the Milky Way.
Now, with galaxies 12b ly away it's a different story. So much new shit is being created those galaxies are shooting away from us at the speed of light
Yes it would have to increase as the universe expands because the density of DE would decrease if it didn't.
Technically we don't know whether space-time isnt stretching as it's not something we can directly measure. This time dilation would happen in both cases I've since learned. Been great to talk it through on here as ever.
Even DE is just theoretical
You know the "Big Rip"? Insane.
Eventually DE could hypothetically tear apart all structures in the universe, from galaxies and stars down to atoms and subatomic particles.
Didn't they (someone) decide that dark energy will most likely never reach a big rip scenario, but "just" the heat death of the Universe?Even DE is just theoretical
You know the "Big Rip"? Insane.
Eventually DE could hypothetically tear apart all structures in the universe, from galaxies and stars down to atoms and subatomic particles.
We don't really know, I think...
Big Crunch vs Big Freeze vs Big Rip.
The BF makes the most sense to me
I was going to write that after your message to McGEven DE is just theoretical
You know the "Big Rip"? Insane.
Eventually DE could hypothetically tear apart all structures in the universe, from galaxies and stars down to atoms and subatomic particles.
about the heat death of the universe etc.The outer reaches of the cosmos is expanding faster than c I think, hence the observable universe.
Same thing I think. Either way it seems strange to confidently predict how the universe will be, based on something we know very little about
Didn't realise that there was that much shit about.
They're both based on the idea that gravity will never reassert itself against dark energy (leading to the big crunch), but they're different.
In the big rip the universe expands quicker and quicker until all matter is ripped apart. In the heat death of the universe it never reaches that point, but still expands endlessly unti there is no longer any potential left, nothing more for entropy to do. If the former is the case the Universe could be over half-way through its life, while if it's the latter it's got a stupid amount of time left.
It might seem strange to predict, but you're talking about astrophysics here. It's not necessarily any stranger than anything else. They aren't just guessing, there's real science that went into it.
I never said they were guessing. But that dark energy is something we know little about. The theory is that by the time the universe was 7b years old dark energy became the dominant force in the univers and the big crunch is no longer a possibility. Dark energy is proportional to space but I'm sure we're just telling each other stuff we already know here. Brian Cox in wonders of the universe frames it as the heat deathbof the universe and states that after a huge amount of time all that will be left will be a sea of photons tending towards absolute zero
Sure, I am just pointing out that the big rip and heat death are two different outcomes with different implications. What Cox describes there is heat death.
Ok maybe I'm remembering it wrong. I thought he said the weak and strong nuclear force of atoms would be broken. All very sobering to contemplate nonetheless
Oh yeah, it's a complete mind-feck whichever one it is. I'm sure we're only going to learn more about it the next few years as well. It's crazy how far the field has come the last 2-3 decades.
What do you all think of this theory that the Universe isn't expanding at all and the observed red-shifting could be due to the evolution of protons/electrons over time?
https://www.livescience.com/physics...ld-be-a-mirage-new-theoretical-study-suggests
https://www.livescience.com/physics...ld-be-a-mirage-new-theoretical-study-suggests
That would be so funny if it turns out to even be somewhat true.
It would mean humanity has no theoretical limit to how far we can spread, which would be cool I guess. As is we're realistically limited to just the Local Group. It's a big just, I grant you, but smaller than "everywhere".
Doubt it's actually true. Don't these astrophysics papers usually have loads of authors by the way? Seems weird that the biggest discovery in decades would be down to just this one guy.
I've no idea about the authors thing. I read about it and didn't see much critique of it anywhere so posted it here in case anyone had any insight.
Noone knows shit.
This is certainly an interesting theory and does resolve a number of the more difficult issues. Like the cosmological constant and dark matter. Best I believe to keep an open mind on these things.
Edit. And if correct would make Einstein a very happy man.
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I recommend watching this as a Planetarium show, but if you can't, the youtube movie is good enough!
5000 Eyes - Mapping the Universe with DESI
The Dark Energy Spectroscopic Instrument (DESI) is creating the most detailed map of our nearby universe. Installed on the Mayall telescope on Kitt Peak in Southern Arizona, DESI's 5000 independently operated robots can measure the light from millions of galaxies at once.
5000 Eyes - Mapping the Universe with DESI
The Dark Energy Spectroscopic Instrument (DESI) is creating the most detailed map of our nearby universe. Installed on the Mayall telescope on Kitt Peak in Southern Arizona, DESI's 5000 independently operated robots can measure the light from millions of galaxies at once.
D'Oh!
Voyager 2: Nasa loses contact with record-breaking probe after sending wrong command
https://www.bbc.co.uk/news/world-66371569
Voyager 2: Nasa loses contact with record-breaking probe after sending wrong command
https://www.bbc.co.uk/news/world-66371569
Somebody's getting fired for that!
Seriously though, it would be devastating news if it's finally lost forever.
Seriously though, it would be devastating news if it's finally lost forever.
Who forget to build an are you sure promptD'Oh!
Voyager 2: Nasa loses contact with record-breaking probe after sending wrong command
https://www.bbc.co.uk/news/world-66371569
Still mind blowing to command something billions of miles away though.
It says in the article it's set up to reset it's antenna to point back at Earth multiple times a year so they reckon it'll be grand in November.
It going to die in around three years anyway. Probably they get it back in October
I thought this should excite all you (us) nerds in this thread:
ESA - Euclid test images tease of riches to come
What Euclid will offer:
ESA - Euclid test images tease of riches to come
What Euclid will offer:
And why they're happy:
Nice pic to go with this (NISP instrument full field of view and zoom-in for detail):